Pneumatic dry powder offset eliminator



' Sept. 2, 1958 s. F. ROONEY, JR 2,850,214

PNEUMATIC DRY POWDER OFFSET ELIMINATOR Filed Feb. 2A, 1956 2Sheets-Sheet 1 LNVENTOR. GEORGE E Roo/vsxJ/e;

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Sept. 2, 1958 G. F. ROONEY, JR

PNEUMATIC DRY POWDER OFFSET ELIMINATOR 2 Sheets-Sheet 2 Filed Feb. 24,1956 NM \m x| 6 mm M mu Rm m mm 0 o vb .W Wm mw w \m W) M m u m m JNW INVEN TOR. GEORGE E ROONEYJR.

PNEUMATIC DRY POWDER OFFSET ELIMINATOR George F. Rooney, In,(Iincinnati, Ohio Application February 24,1956, Serial No. 567,655 2Claims. (Cl. 222-493) This invention relates to a device for sprayingpowder particles on printed sheets as the printed sheets are deliveredby a printing press, to prevent undesired oifset printing.

An object of this invention is to provide a device for spraying powderhaving a container in which powder particles are sufiiciently agitatedto form a mist or suspension in the container at a level above thenormal level of the body of powder therein, the mist of powder beingdischarged from the container into distributing lines 'from whichdiscrete puffs of powder issue.

A further object of this invention is to provide a device of this typein which air is introduced into a powder container in two streams oneinto the body of the powder to agitate the same and the other into theair-powder suspension to discharge the same into the distribution lines.

A further object of this invention is to provide a device of this typein which an air inlet line discharges into the lower portion of thecontainer below the powder level in such a direction as to stir thepowder by driving the powder circumferentially of the container.

A further object of this invention is to provide a novel and efiicientmechanism for operating an air supply valve for the container wherebydiscrete pufis of powder particles are delivered to printed sheetsissuing from the printing press in timed relation therewith and air foragitating the powder is provided.

A further object of this invention is to provide a device of this typehaving an air line, a valve therein for delivering air to the powder inthe container, and a mechanism for operating the valve at timedintervals to eifect delivery of discrete puffs of powder particles toprinted sheets in timed relation to the delivery of the sheets by thepress.

The above and other objects and features of this invention will beapparent to those having ordinary skill in the art to which thisinvention pertains, from the following detailed description and thedrawings:

In the drawings:

Figure 1 is a perspective view showing a powder spray ing deviceconstructed in accordance with an embodiment of this invention, thedevice being shown mounted at the delivery end of a printing press, onlya fragmentary portion of the printing press being shown.

Fig. 2 is a view in vertical section of the powder container of thedevice;

Fig. '3 is a view in section taken on the line IIIIII in Fig. 2;

Fig. 4 is a fragmentary view in section, taken on the line IVIV in Fig.2;

Patent Fig. 5 is an enlarged view in side elevation of the valve andvalve operating mechanism of the device illustrated in Figs. 1, 2, and3;

Fig. 6 is a view in side elevation of the valve and valve operatingmechanism in another position; and

Fig. 7 is a view in side elevation showing the valve and valve operatingmechanism in a further position.

ice

In Fig. l the delivery end of a printing press is indicated at 10.Details of construction of the printing press are omitted and only asmuch of the delivery end of the press is shown as is necessary for anexplanation of the invention. At the delivery end of the printing press,piles of printed sheets 12 are accumulated on sheetholding boards 14.The boards 14 are supported on beams 16 which are gradually lowered asthe stack of sheets gets higher and higher. Also at the delivery end ofthe press are frame members or posts, two of which are indicated at 17and 18. The frame member or post 17 supports a crank 19 which swings intimed relation with the delivery of printed sheets. The mechanismdescribed to this point forms a part of printing presses which arepresently in common use for printing box board and the like.

On post 17 is mounted a bracket 21 which supports a powder container 23into the chamber of which air under pressure is delivered by an airvalve 24 disposed in an air supply line 26. The air passes through anair filter 27 and a pressure reducing valve 28. From the air valve 24,the air passes through a T-fitting 29 to lines 31 and 32 leading to theupper part and the bottom of the container, respectively. Powder fromthe container 23 is distributed by powder distributing lines 34 havingnozzles 36 at the discharge ends thereof. The nozzles 36 are disposedabove the pile of sheets 12 and are arranged to distribute powder on thesheets as they are delivered from the press.

The air valve is actuated by valve operating mechanism indicatedgenerally at 38, that is actuated by the crank 19. As the crank 19swings to the right, as indicated in Fig. l, the valve is opened toprovide an air blast to the container. The air delivered to the bottomof the container agitates the powder and forms an air-powder suspensionin the upper part of the container. The air blast delivered by pipe 31distributes the powder-air suspension to the printed sheets. As thecrank 19 swings back to the left, the air supply and consequently thedis- The powder container The powder container 23, as illustrated inFig. 2, includes a fiat bottom plate 41 and an upright cylindrical wall42. At the upper end of the cylindrical wall 42 is an outwardlyextending flange 43. The powder container is closed by a cap 44 which issealed to the flange 43 by an appropriate gasket 46. A stud 47 attachedto the bottom plate 41 extends upwardly through the container. A nut 48on the stud 47 holds the cap 44 in closed position.

The air inlet line 351 communicates with the upper portion of theinterior of the container through an opening 49 in the wall thereof. Thepowder distributing lines 34 communicate with the upper portion of thecontainer through openings 51. The powder distributing lines areopposite the air inlet opening 49 'so that the flow of air from pipe 31to lines 34 crosses the upper portion of the container. The air inletopening 49 and outlet openings 51 are horizontal and substantiallyaligned so that the blasts or puffs of air drive powder mist directlyacross of the powder distributing lines may be used as'desired or theneeds require.

The air supply line 32 has a needle valve 52 therein. From the needlevalve 52 air passes through a nipple 53 which extends through an opening54 in the lower portion of the container. An elbow fitting 56 is mountedon the inner end of the nipple 53, and, as shown in Figs. 2 and 4,extends downwardly and circumferentially of the container at an angle ofapproximately 45 to the vertical. Thus, air delivered by line 32 andelbow fitting 56 is discharged downwardly and circumferentially to stirup and agitate the powder in the container so that a mist or suspensionof air and powder is formed above the normal level of powder in thecontainer. This mist of powder is discharged to the distribution lines34, in the manner stated supra, to the nozzles 36. As indicated in Fig.1, nozzles 36 are supported on an appropriate frame 57 which extendsabove the printed sheets so that the powder is distributed onto thesheets as the sheets are stacked.

The needle valve 52 is opened only slightly, so that the major portionof air passing through the air valve 24 enters through the line 31 toprovide a substantial puff for driving air through the lines 34. Theamount of powder that is distributed with each puff may be controlled byadjusting the opening of the needle valve 52 to increase or decrease thedegree of agitation of the powder and the density of the powder mist inthe upper part of the chamber of container 23.

Powder is maintained in the container at levels between a minimum levelA and a maximum level B (see Fig. 2). At all times there is a chamberspace above the powder level in communication with the openings 49 and51. In addition, the level of powder is maintained above the elbow 56 sothat the powder-agitating air is discharged below the powder level intothe powder.

An electric heater 57a is attached to the wall of the container andserves to keep the powder in the container warm and prevent condensationof moisture inside the container.

The air valve The operation of the air valve 24 and the valve actuatinmechanism 38 is most clearly shown in Figs. -7 inclusive. The air valve24 has an air inlet 58 and a discharge 59. A plunger 61 actuates the airvalve. The plunger 61, in turn, is actuated by an upright lever 62 whichis pivotally attached at its lower end to the hous ing of the valve.pivotally mounted a head member 63. The head member 63 is .provided witha bore 64 through which a rod 66 extends. The rod 66 is Z-shaped and hasarms 66a and 66b and a cross bar 660. Arm 66a may be adjusted along thebore 64. The rod is held in adjusted position by a set screw 67.Adjustment of the rod along the bore 64 determines the time of the startof powder delivery.

A stop rod 72 is attached to the head member 63 and is engageable with alug 73. The lug 73 is mounted on an adjustable bar 74 mounted on thebody of the air valve. Bar 74 is slotted, as indicated at 75, so thatthe bar 74 can be adjusted to either raise or lower the position of thelug 73. The stop rod 72 engages the lug 73 when the valve actuatinglever 62 and the rod 66 are in the position shown in full lines in Fig.5. Adjustment of bar 74 determines the end of powder delivery.

The valve-actuating crank 19 is provided with a lug 76 at the upper endthereof. The lu 76 is engageable with the cross bar 600 of the rod 66.The crank 19 is driven by a rod 77, only a portion of which is shown,forming a part of the printing press mechanism. Rod 77 rec1procates backand forth in timed relation to the delivery of printed sheets and swingsthe crank 19 with an oscillating motion. Thus, the crank 19 oscillatesin timed relation with the operation of the sheet delivery mechanism ofthe printing press.

At the upper end of the lever 62 is When the crank 19 is in the positionshown in dot-dash lines in Fig. 5, lug 76 engages arm 66b of the rod 66and holds the rod in raised position. The crank 19 swings to the rightto the position shown in full lines in Fig. 5 and through that positionto the position shown in Fig. 6 in which the lug 76 engages the crossbar of the rod 66 to urge the rod and the valve actuating lever to theright to actuate the valve and permit air to pass through the valve.

As the crank 19 advances farther to the right, the lug 76 passes belowthe lower end of the cross bar 66a, and the rod 66 rides on the crank asshown in Fig. 7, whereupon the valve 24 is closed by actuation of thevalve spring (not shown) of the valve. Then, the crank 19 swings back tothe left to the position shown in dot-dash lines in Fig. 5, whereuponthe cycle is repeated.

Conclusion As sheets are delivered from the printing press, air isdirected into the powder container 23 in puffs, so that, as each sheetis delivered, a puff of powder is distributed to the sheet to coat thesheet and prevent offset printing.

The air valve and piping arrangement provide two supplies of air to thepowder container. One supply is directed into the lower portion of thecontainer to stir and agitate the powder so that a mist or suspension ofpowder is formed in the upper portion of the container. The other airsupply is directed into the upper portion of the container and eifectsdelivery of the mist to the nozzles.

The powder used may be of the type usually used in preventing offsetprinting.

The construction of the device is very simple. However, the devicecauses uniform delivery of a puff of pow der to each sheet,notwithstanding variations in level of powder in the container.

The powder spraying device illustrated in the drawings and describedabove is subject to structural modification without departing from thespirit and scope of the appended claims.

Having described my invention, what I claim as new and desire to secureby letters patent is:

1. A device for spraying powder particles which comprises an enclosed,upright, hollow, cylindrical, powderholding container having itsinterior substantially free of obstructions and having a flat,horizontal bottom plate, powder partially filling the container, ahorizontal air inlet in the upper portion of the wall of said containerfor discharging air across the upper portion of the interior of thecontainer above the level of the powder, a powder distributing line incommunication with the interior of the cylinder and positioned in theopposite wall of said container, said distributing line being insubstantially the same horizontal plane as the air inlet whereby powderin the container between said air inlet and said powder distributingline is forced through said distributing line, another air inletadjacent the lower end of the container below the powder level, meansattached to the lower air inlet for directing air therefromcircumferentially of the container, means for supplying timed puffs ofair to the air inlets whereby powder is stirred and forced between theupper air inlet and the discharging line, means for connecting said airinlets together and means for throttling the flow of air into said lowerair inlet to control the degree of agitation of the powder in thecontainer.

2. A device for spraying powder particles as defined in claim 1 in whichsaid lower inlet is directed downwardly and circumferentially of thecontainer.

References Cited in the file of this patent UNITED STATES PATENTS1,592,806 Brunell July 13, 1926 2,257,010 Hildebrand Sept. 23, 19412,496,194 Bennett Ian. 31, 1950 2,720,342 Fleck Oct. 11, 1955 2,729,194Jones Ian. 3, 1956

